1. Technical Field
The present invention relates to a detection device capable of detecting an external proximity object, and more particularly, to a detection device capable of detecting an external proximity object based on a change in capacitance, and a display device.
2. Description of the Related Art
In recent years, attention has been paid to a detection device referred to as a touch panel capable of detecting an external proximity object. The touch panel is mounted on or integrated with a display device such as a liquid crystal display device and is used for a display device with a touch detection function. The display device with a touch detection function displays various button images on the display device, thereby enabling input of information using the touch panel instead of ordinary mechanical buttons. The display device with a touch detection function, which includes such a touch panel, does not require an input device such as a keyboard, a mouse, and a keypad, and the use of the display device tends to increase in a portable information device such as a mobile phone as well as in a computer.
There are several types of touch detection methods, including an optical type, a resistance type, and a capacitance type. When a touch detection device of the capacitance type is used in a mobile device and the like, a device having a relatively simple structure and low power consumption can be provided. For example, Japanese Patent Application Laid-open Publication No. 2010-197576 (JP-A-2010-197576) discusses a touch panel in which a transparent electrode pattern is configured to be invisible.
Now, the detection devices capable of detecting an external proximity object are going to be formed to be thin, have a large screen, or have high precision, and accordingly, low resistance of detection electrodes is required. For the detection electrodes, as a material of transparent electrodes, a transparent conductive oxide such as indium tin oxide (ITO) is used. In order to configure the detection electrodes to have low resistance, a conductive material such as a metal material may be effectively used. However, when the conductive material such as the metal material is used, moire may be visually recognized due to interference between pixels of a display device and the conductive material such as the metal material.
Further, Japanese Patent Application Laid-open Publication No. 2014-041589 (JP-A-2014-041589) discusses a detection device capable of lowering a possibility of moire to be visually recognized even if a detection electrode made of a conductive material such as a metal material is used. Although the detection device discussed in JP-A-2014-041589 can lower the possibility of the moire to be visually recognized, when visible light is incident, a light intensity pattern, in which light is diffracted or scattered by a plurality of detection electrodes, becomes close to a pattern in which a plurality of points of light are scattered, and the points of light may be visually recognized.